1. Field of the Invention
The present invention relates to a one piece composite guitar body and, more particularly, pertains to tailoring the sound produced by a stringed instrument by virtue of its construction.
2. Description of the Prior Art
Guitar bodies may be classified into 2 general types: electric and acoustic. The electric guitar body is traditionally solid, comprised typically of solid wood or wood laminations. The acoustic guitar body, relying solely on the vibration of the sound board and box, is traditionally hollow by design. This invention describes an improved guitar body made from composite materials that can be made into either an electric guitar body, or an acoustic guitar body, or a variation in between.
Traditionally, a solid body stringed instrument is one wherein the body lacks a cavity and a soundboard and which carries one or more electrical pickups. These pickups transform the string vibrations into electrical signals which are subsequently amplified and usually modified and then transformed into sound waves to create sounds related to string vibrations. Commonly, these bodies have been made from solid pieces of wood which are carved to define specific shapes including various recesses and openings for receiving bridges, pickups, and other components attached to the bodies.
The type of wood used on solid bodies varies but is limited to densities between 0.3 g/cm3 and 0.6 g/cm3 so that the weight and tonal qualities of the guitar are retained. These preferred woods are expensive and in some cases, rare and exotic. Some examples are basswood, swamp ash, alder, mahogany, and maple.
Despite the fact that electrical pickups in the solid body transform the string vibrations into various sounds, the solid body also effects the tone of the guitar. For example, softer woods such as basswood produce a somewhat deader, softer tone while harder woods such as alder produce a slightly brighter note with more sustain. This is because of the sympathetic relationship between the strings and the body. For example, a harder, stiffer wood will transmit string vibrations faster resulting in a note with more attack and a brighter sound.
It should be noted that these variations in tone due to different woods are limited because wood itself is limited to its internal structure of aligned cellulose fibers. Because of this, wood can be termed nearly homogeneous. The sound differences generated by different wood types can sometimes only be detected by an expert. Often, the type of strings and pickups used produce more tonal difference than the type of wood used.
The problems related to wood bodies for electric guitars have been numerous. Wood bodies, for example, change dimension when exposed to changes in temperature, humidity, or other environmental factors. These dimensional changes, at a minimum, result in tonal variations due to tension changes in the string and scale length changes. Long term effects can be more drastic such as warping and cracking which can leave the guitar useless.
Still another problem with wood used for solid body electric guitars is the large variation in densities of woods currently used. The fluctuations of density throughout a wood genus leave the guitar manufacturer in the position of manufacturing guitars which span a large range of weights and tonal qualities.
Additionally, wood used for the body of an electric guitar cannot withstand bumps normally associated with guitar playing, resulting in dents caused by such impacts.
There have been several attempts to create an electric guitar body using alternative synthetic materials. These attempts, however, have failed as a successful replacement for wood.
In the case of U.S. Pat. No. 5,054,356 of Farnell, Jr., a guitar body is described made primarily of rigid closed cell foam which is partially covered and bonded to flat panels of plastic sheet material having a thickness of about 2.5 mm (0.1 inches). An edge wall of plastic material is subsequently wrapped around the plastic sheet and foam sandwich thereby leaving the foam exposed. The theory is that the cells of the foam alternately pressurize and depressurize to enhance the musical output of the guitar. Because the foam is exposed, a deader sound is generated.
In the case of Cove, U.S. Pat. No. 4,185,534, the use of a foamed polymeric material to fabricate the body necessitated the neck continuing through the entire body. This is because the foam alone, due to the lack of structural fiber resin reinforcement, is not strong enough to hold the strings at tension. Furthermore, the large presence of exposed foam deadens the tone of the guitar and makes it susceptible to impact damage.
In U.S. Pat. No. 4,290,336 by Peavey, the body is molded into two major portions, like a clamshell, necessitating a secondary operation of screwing the two halves together. This method requires the addition of a trim molding in order to conceal the seam where the two halves are joined together. In addition, this design has connectors between the top and bottom surfaces, which limits the vibrational response of the shell of the body, which will reduce the tonal qualities of the guitar body. This results in a body with numerous interfaces which creates relative movement and damps the sustain of the note. This design, therefore, needs only polymeric materials, not composite materials as described in the present invention.
In the case of U.S. Pat. No. 4,334,453 of Morrison, a plastic shell is molded around a reduced dimension wood core. The wood is left exposed in the region of the pickups in order to retain the desired sound of wood. This invention produces essentially a wood guitar body with a plastic cover. The purpose of this method is to reduce the cost of the guitar body without having the inferior tonal qualities of plastic. This design does not behave like a unitary shell as described in the present invention.
In the case of Fishman, et. al. in U.S. Pat. Nos. 5,189,235, 5,305,674, and 5,337,644, a guitar body is described which is first cut out of a light weight soft wood, then covered with carbon fiber and fiberglass prepreg and bonded together in a secondary operation using a common vacuum bag process for consolidation pressure. The composite outer laminate offers reinforcement for the weaker soft wood used. This combination is used to produce a light weight guitar body but requires thin shapes in order to achieve the desired light weight. Furthermore, this design does not behave like a unitary shell as described in the present invention.
In the case of Soika, et. al., U.S. Pat. No. 4,144,793, a one piece acoustic guitar body is created through the use of conventional spin or rotocasting techniques. The body created is hollow, polymeric, and without fiber reinforcement. Due to the lack of fiber reinforcement, the design is limited because of the superior strength of the fiber composite and the lacks the options of customizing the tone of the guitar by varying the fiber type and orientation.
There have also been attempts to produce a hollow acoustic guitar body, but none have achieved the desired performance of a unitary shell of the present invention.
In the case of Jones, U.S. Pat. No. 4,213,370, a hollow plastic body is described with a rigid vertical outside wall, connecting to a sound board using a joint design. Although the patent mentions fiber reinforcements, it is proposed to produce this part via injection molding, thus limiting the fibers to short lengths without orientation. This limits the design due to limited strength, as evidenced by the bracing required and the joint design to attach the sound board. In the present invention using a unitary shell of continuous fiber reinforcement, the need for bracing and complex joint design is eliminated.
In the case of John, U.S. Pat. No. 4,408,516, a graphite fiber violin is described where the sound box of the violin is made from carbon fiber prepreg material. The top and bottom sound boards and side wall section are produced separately, then assembled together using a flexibilized epoxy glue. The top and bottom sound boards are connected using a brass sound post. Although this design using oriented fiber reinforcement, it is not a unitary shell by design, since the top and bottom sound boards and side wall section are molded separately. Finally, the sound post which connects the top and bottom sound boards limits the vibrational response of the body to act as a unitary shell.
While these devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not describe a one piece guitar body that allows tailoring the sound produced by a stringed instrument by virtue of its construction.
In this respect, the one piece composite stringed instrument according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of generating sounds which may be varied by varying the construction.
Therefore, it can be appreciated that there exists a continuing need for a one piece composite guitar body which can tailor the sound produced by virtue of its one piece composite construction. In this regard, the present invention substantially fulfills this need.
In view of the foregoing disadvantages inherent in the known types of guitars now present in the prior art, the present invention provides an improved one piece composite guitar body for providing tailored sounds. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a one piece composite guitar body which has all the advantages of the prior art and none of the disadvantages.
To attain this, the present invention essentially comprises an electronic guitar body for tailoring the sound produced by virtue of a one piece composite construction. Such construction comprises, in combination a front face and a parallel back face having a common shape formed with a lower curved edge and an upper sinusoidal edge with a central neck pocket formed therein and with sinusoidal side edges there between. The body also has a continuous side face there around between the edges of the front face and the edges of the back face and with an essentially common distance between the majority of the extents of the front face and the back face. Also part of the combination is a plurality of discontinuities formed within the front face. Such discontinuities include a hole for bridge installation extending from the front face to the back face and also include a plurality of electronic cavities extending downwardly from the front face to a distance less than the distance between the front face and the back face. Also included within the combination is an interior one-piece core with an exterior surface fabricated of a rigid foam of a type adapted to abate shrinkage during the heat of molding, preferably polyurethane. Lastly as part of the combination is an exterior laminate in intimate contact with the entire exterior surface of the core, the exterior laminate being formed of a plurality of composite layers including an interior layer of linearly aligned strand or fibers. All of the strands are essentially inextensible fibers, preferably fiberglass. The strands of each layer are enveloped in an associated polymeric binder, preferably epoxy. The interior most ply includes linearly aligned fibers or strands in intimate contact with the core and with each subsequent layer being in intimate contact with the next adjacent layer.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims attached.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of descriptions and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
It is, accordingly, an object of this invention to create a composite guitar body with a continuous unitary shell and optional internal core where the body has:
tonal qualities of attack, sustain, and harmonics which can be varied by design to achieve the type of sound desired.
a predictable and repeatable sound from part to part.
replicated the sound of popular wood bodies.
a unique tonal response by utilizing fibers in specialized directions of orientation.
resistance to changes in temperature and humidity.
a high strength to weight ratio.
different degrees of stiffness and density in various parts of the body to achieve unique tonal responses.
eliminated the costly and laborious finishing method through the use of an exterior gelcoat.
the behavior of a single component body.
It is another an object of the present invention to provide a one piece composite guitar body which has all of the advantages of the prior art guitars and none of the disadvantages.
Even still another object of the present invention is to provide a one piece composite guitar body for tailoring the sound produced by virtue of a one piece composite construction.
Lastly, it is an object of the present invention to provide a body for a stringed instrument comprising a front face and a back face and a continuous side face there around; and an exterior laminate, the exterior laminate being formed of a plurality of composite layers including an interior layer, the composite layers of the laminate also including at least one supplemental layer, all of the strands being essentially inextensible fibers, the strands of each layer being enveloped in an associated polymeric binder, with each subsequent layer being in intimate contact with the next adjacent layer.
These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.